Buggy code:
public static final int ENUMERATE_VALUES_NO_ITERATOR = 4 ; public static final int ENUMERATE_ARRAY_NO_ITERATOR = 5 ; public static Object enumInit ( Object value , Context cx , int enumType ) { } public static void setEnumNumbers ( Object enumObj , boolean enumNumbers ) { } public static Boolean enumNext ( Object enumObj ) { } public static Object enumId ( Object enumObj , Context cx ) { } public static Object enumValue ( Object enumObj , Context cx ) { } private static void enumChangeObject ( ScriptRuntime . IdEnumeration x ) { } public static Callable getNameFunctionAndThis ( String name , Context cx , Scriptable scope ) { } public static Callable getElemFunctionAndThis ( Object obj , Object elem , Context cx ) { } public static Callable getPropFunctionAndThis ( Object obj , String property , Context cx ) { } public static Callable getPropFunctionAndThis ( Object obj , String property , Context cx , final Scriptable scope ) { } private static Callable getPropFunctionAndThisHelper ( Object obj , String property , Context cx , Scriptable thisObj ) { } public static Callable getValueFunctionAndThis ( Object value , Context cx ) { } public static Ref callRef ( Callable function , Scriptable thisObj , Object [ ] args , Context cx ) { } public static Scriptable newObject ( Object fun , Context cx , Scriptable scope , Object [ ] args ) { } public static Object callSpecial ( Context cx , Callable fun , Scriptable thisObj , Object [ ] args , Scriptable scope , Scriptable callerThis , int callType , String filename , int lineNumber ) { } public static Object newSpecial ( Context cx , Object fun , Object [ ] args , Scriptable scope , int callType ) { } public static Object applyOrCall ( boolean isApply , Context cx , Scriptable scope , Scriptable thisObj , Object [ ] args ) { } static Object [ ] getApplyArguments ( Context cx , Object arg1 ) { } static Callable getCallable ( Scriptable thisObj ) { } public static Object evalSpecial ( Context cx , Scriptable scope , Object thisArg , Object [ ] args , String filename , int lineNumber ) { } public static String typeof ( Object value ) { } public static String typeofName ( Scriptable scope , String id ) { } public static String typeofName ( Context cx , Scriptable scope , String id ) { } public static Object add ( Object val1 , Object val2 , Context cx ) { } public static CharSequence add ( CharSequence val1 , Object val2 ) { } public static CharSequence add ( Object val1 , CharSequence val2 ) { } public static Object nameIncrDecr ( Scriptable scopeChain , String id , int incrDecrMask ) { } public static Object nameIncrDecr ( Scriptable scopeChain , String id , Context cx , int incrDecrMask ) { } public static Object propIncrDecr ( Object obj , String id , Context cx , int incrDecrMask ) { } private static Object doScriptableIncrDecr ( Scriptable target , String id , Scriptable protoChainStart , Object value , int incrDecrMask ) { } public static Object elemIncrDecr ( Object obj , Object index , Context cx , int incrDecrMask ) { } public static Object refIncrDecr ( Ref ref , Context cx , int incrDecrMask ) { } public static Object toPrimitive ( Object val ) { } public static Object toPrimitive ( Object val , Class < ? > typeHint ) { } public static boolean eq ( Object x , Object y ) { } public static boolean isPrimitive ( Object obj ) { } static boolean eqNumber ( double x , Object y ) { } private static boolean eqString ( CharSequence x , Object y ) { } public static boolean shallowEq ( Object x , Object y ) { } public static boolean instanceOf ( Object a , Object b , Context cx ) { } public static boolean jsDelegatesTo ( Scriptable lhs , Scriptable rhs ) { } public static boolean in ( Object a , Object b , Context cx ) { if ( ! ( b instanceof Scriptable ) ) { <START_BUG> throw ScriptRuntime . typeError0 ( "msg.instanceof.not.object" ) ; <END_BUG> } return ScriptRuntime . hasObjectElem ( ( ( Scriptable ) ( b ) ) , a , cx ) ; } public static boolean cmp_LT ( Object val1 , Object val2 ) { } public static boolean cmp_LE ( Object val1 , Object val2 ) { } public static ScriptableObject getGlobal ( Context cx ) { } public static boolean hasTopCall ( Context cx ) { } public static Scriptable getTopCallScope ( Context cx ) { } public static Object doTopCall ( Callable callable , Context cx , Scriptable scope , Scriptable thisObj , Object [ ] args ) { } static Scriptable checkDynamicScope ( Scriptable possibleDynamicScope , Scriptable staticTopScope ) { } public static void addInstructionCount ( Context cx , int instructionsToAdd ) { } public static void initScript ( NativeFunction funObj , Scriptable thisObj , Context cx , Scriptable scope , boolean evalScript ) { } public static Scriptable createFunctionActivation ( NativeFunction funObj , Scriptable scope , Object [ ] args ) { } public static void enterActivationFunction ( Context cx , Scriptable scope ) { } public static void exitActivationFunction ( Context cx ) { } static NativeCall findFunctionActivation ( Context cx , Function f ) { } public static Scriptable newCatchScope ( Throwable t , Scriptable lastCatchScope , String exceptionName , Context cx , Scriptable scope ) { } private static boolean isVisible ( Context cx , Object obj ) { } public static Scriptable enterWith ( Object obj , Context cx , Scriptable scope ) { } public static Scriptable leaveWith ( Scriptable scope ) { } public static Scriptable enterDotQuery ( Object value , Scriptable scope ) { } public static Object updateDotQuery ( boolean value , Scriptable scope ) { }

Fix:
throw ScriptRuntime . typeError0 ( "msg.in.not.object" ) ;